原创 Inamorata prognostication engine design (Part 2)

Well, I'm quite pleased to inform everyone that things are racing along with regard to my Pedagogical and Phantasmagorical Inamorata Prognostication Engine project. I have all sorts of amazing news to share, plus I could do with some advice.

Let's start with the current state-of-play regarding the layout of the control panel as illustrated below. As you may recall, there are going to be five potentiometers (the second column from the left in the upper portion of the panel). These will be used to input baseline data values concerning one's inamorata, including things like personality and overall mood and disposition.

Surrounding each potentiometer will be 16 tri-colour LEDs, and it's the way in which these LEDs are used that requires your advice. But first I have some mega-cool news; based on a suggestion from my chum, Rick Curl, I've decided to use motorized potentiometers as illustrated below:

These little beauties are Bourns 10K Linear Potentiometers (part number 652-PRM162K420K103B1 from Mouser Electronics). First I ordered one to check it out. This little beauty arrived just a few minutes ago as I pen these words. We immediately whipped it up on the testbench and it works perfectly. The geared motor is incredibly quiet and the potentiometer turns very smoothly, so I've just placed a follow-up order for the remaining four units.

The idea is that if one's inamorata should take it into her mind to vary any of the baseline settings you've established, the other potentiometers will automatically change to compensate (a few minutes later they will all return to their original settings). You have to admit that this is rather clever.

As an aside, the toggle switches I'm using are little antique rascals with small white bobbles on the ends of their actuators as illustrated below. Generally speaking, these switches look really amazing, except for the part that will be bolted to the front panel, but I have a solution...

I bounced over to the plumbing section of my local Lowes hardware store and found a dome-shaped copper fitting as shown in the image above. I purchased a bunch of these "domes"—one for each toggle switch on the front panel. I'm planning on chopping the lower segment off each dome and milling a slit in the top to accommodate the switch's actuator. I'm also going to "age" both the main brass panel and these copper domes so they won't look quite so shiny; the Steampunk look I'm aiming for is something that wouldn't have appeared out of place in a Victorian setting (apart from the pulsing LEDs, of course).

If you compare the latest rendition of the front panel to the original version, you will observe the elaboration of one of the elements—the multi-push-button switch assembly in the lower middle of the upper panel (I only recently took delivery of this little scamp). This is an antique telephone switch assembly as illustrated below:

This looks and feels really great. The only problem is the black "JKL 5," "MNO 6," PRS 7," etc. annotations on the top of the white buttons as illustrated below:

As far as I can tell, these annotations aren't embossed into the buttons, but are instead printed onto them (although I could be wrong). Somehow I have to remove or cover these annotations without negatively affecting the "character" of the assembly. Do you have any suggestions?

Moving on... As you may recall, each toggle switch and momentary pushbutton is going to have two associated tri-colour LEDs as illustrated below. These are going to be implemented using Adafruit's NeoPixels, although—at the time of this writing—I've not yet decided whether to chop individual pixels off a NeoPixel Strip or use Flora Versions, which are available in sheets of 20.

In the case of the potentiometers, the 16 LEDs surrounding them will be implemented using NeoPixel Rings as illustrated below. Observe the small white "dots" shown in this image. These 5mm diameter dots—which look like mother-of-pearl—will be mounted flush with the brass panel. I think this is going to look incredibly sophisticated.

As it happens, there can be complications with regard to using real mother-of-pearl, but I found some amazing acrylic imitation mother-of-pearl equivalents—called Pearloid Dots—from the Stewart MacDonald company, which offers "Everything for building and repairing stringed instruments" (these dots are originally intended to be used as inlays in the frets of guitar necks).

At first I was worried that the light from a NeoPixel wouldn't pass through the Pearloid Dot, so I purchased one to play with—it works perfectly and looks soooooo coooooool!

All of which leads us to the part where I'm interested in hearing your thoughts. The potentiometers can be rotated through a 300 degree sweep, which means the pointer won't be able to point to three of the pixels—say the three shown in blue below:

Now, we could simply decide to not drill these three holes through the front panel, but that would we wasting three LEDs, and as far as I'm concerned you can't have too many LEDs. Also, who is to say that we might not replace these potentiometers with ones that have a larger (or smaller) sweep capability in the future? Quite apart from anything else, we can use these three LEDs as part of the self-destruct sequence should anyone be foolish enough to press the "Moderately-Sized Red Button" in the bottom panel. Even in their un-used condition, we can still light them up with some default colour (any suggestions?).

Now consider the rest of the LEDs. I'm trying to decide how we should use these to reflect the current state of the potentiometer. Remember that these are individually-controllable tri-state LEDs, each of which can be assigned any colour and set to any level of brightness (from fully off to fully on). Purely for the sake of argument, let's start by assuming that we shall employ only two colours: green = good and red = not-so-good. In this case, it seems to me that we have two main choices as illustrated below:

Suppose we are considering "Overall Mood," for example. At one extreme we might have something like "Generally Cheerful"—at the other we might have "Be Afraid, Be Very Afraid" (this is illustrated on the left-hand dial). Alternatively, we could say that the centre position is the one we would prefer, with different negative options on either side (this is illustrated on the right-hand dial). The advantage of the first option is that it's conceptually and visually simple; the advantage of the second option is that it offers more conceptual and visual interest.

Of course, we aren't limited to only two colours—we could go from green to yellow or orange to red—in which case the original approach of ranging from one extreme to another might be best as we have only a limited number of pixels.

The next thing to consider is that we could leave all of the pixels fully on with their designated colours, and simply use the white line on the knob to indicate the current state setting; this is illustrated in the left-hand portion of the image below:

Alternatively, the default state of the red and green pixels could be set to be on, but at a lower intensity. As one rotates the knob clockwise, the pixels could be brought up to full brightness; this is illustrated in the right-hand portion of the image above.

And we aren't limited to having only static (on, off, dim, bright) values—we can easily set individual LEDs to flashing (or "breathing"), for example. The bottom line is that the world is our lobster (or crustacean of your choice). We can do anything we want with these LEDs, limited only by our imaginations. Furthermore, we aren't locked into any particular scheme; we can try multiple scenarios and select the one that is the most mentally stimulating and visually appealing.

The point is that "two heads are better than one," as they say. I have some ideas of my own, but I bet that you do too, and it may well be that your ideas blow mine out of the water. So what do you say? How do you think these rotary LED displays should work? Which of the above base schemes do you prefer (good-to-bad, or bad-to-good-to-bad)? Should we display just two main colours (green and red, or orange and red, or...) or multiple colours? Should we simply specify the brightness of the LEDs as static quantities, or should we have some of them flashing or breathing? Any suggestions will be very gratefully received.